This invention relates to a replaceable torsion assembly or unit and more particularly to a tubular resilient member attached at opposite ends to members which are generally made of metal and internally supported by a tubular member to provide a spring assembly.
Heretofore, torsion units have been made by concentrically positioning cylindrical sleeves of metal of different diameters and securing the resilient material therebetween. The inner metal sleeve is secured to a first element such as an axle, which is to be resiliently carried for torsional movement and the outer cylindrical sleeve is secured to another or second element such as a housing and with respect to which the first element (such as an axle) has relative torsional movement.
Limitation in the actual application of these units are encountered where large relative movement between the elements or members is required. In these instances rubber torsion springs in series or metal coil springs or groups of springs have been used exclusively to take care of the excessive travel. These solutions are heavy and bulky. The instant invention employs a novel combination of elements with an elongated cylindrical rubber member to provide for an unusual result in spring assemblies.
The invention provides a practical and economical means for overcoming an otherwise awkward impractical construction where a large torsional movement is required with a relatively low spring rate.
The term resilient material as employed in this specification and in the claims includes any of a variety of elastomeric materials and, specifically, natural rubber in any of its compounded forms, artificial or synthetic rubber in any of its various forms and any similar materials.